<!DOCTYPE html>
<html lang="en">
    <head>
        <meta charset="UTF-8">
        <meta http-equiv="X-UA-Compatible" content="IE=edge">
        <meta name="viewport" content="width=device-width, initial-scale=1.0">
        <title>Document</title>
    </head>
    <body>
        <div id="app">
            <p v-show="score<0">show</p>
            <p v-html="value+score"></p>
            <p v-text="value+score"></p>
            <p>{{value+score}}</p>
            <button @click="toggle">toggle</button>
            <div v-if="score>80">优秀</div>
            <div v-else-if="score>60">及格</div>
            <div v-else>不及格</div>
        </div>
        <script src="my-vue.js"></script>
        <script>
        var vm = new Vue({
            el:'#app',
            data:{
                value:'A',
                score:50
            },
            methods:{
                toggle(){
                   if(this.score ===50){
                    this.score = 70;
                   }else if(this.score === 70){
                    this.score =90
                   }else{
                    this.score = 0;
                   }
                }
            }
        });
        
    </script>
    </body>
</html>